Dawn Reis Ecological Studies.

Transcription

1 Dawn Reis Ecological Studies

2 Laguna Salada Sharp Park s Federal & State Protected San Francisco Garter Snake (Thamnophis sirtalis tetrataenia) and California Red-legged Frog (Rana draytonii)

3 Goals 1) Introduce you to two key characters at Sharp Park 2) Briefly Summarize their habitat needs 3) Provide a big picture view of key concepts as presented in: ESA PWA. Feb 9, Conceptual Ecosystems Restoration Plan and Feasibility Assessment: Laguna Salada, Pacifica, California. Prepared for the Wild Equity Institute. Prepared by, ESA PWA with Peter Baye, Ph.D, Dawn Reis Ecological Studies.

4 Where To Get More Information: There are lots of details on both SFGS and CRLF habitat needs and specifics restoration design recommendations in the Conceptual Ecosystems Restoration Plan. For SFGS and CRLF information, please see: Chapter 5 Existing Conditions Ecological Assessment Chapter 6 Conceptual Restoration Plan Appendix C Laguna Salada Ecological Assessment

5 PROTECTED UNDER THE FEDERAL ENDANGERED SPECIES ACT (ESA): Endangered Species San Francisco Grater Snake Threatened Species California red-legged frog

6 STATE PROTECTED BY THE STATE ENDANGERED SPECIES ACT Endangered Species - San Francisco Grater Snake STATE PROTECTED AS A SPECIES OF SPECIAL CONCERN California Red-legged Frog

7 FEDERAL ENDANGERED SPECIES ACT Endangered Species An animal or plant species in danger of extinction throughout all or a significant portion of its range. Threatened Species An animal or plant species likely to become endangered within the foreseeable future throughout all or a significant portion of its range.

8 San Francisco Garter Snake (Thamnophis sirtalis tetrataenia) Reasons for Population Decline Habitat removal Vehicles Non-native predators (crayfish, fish and bullfrogs) Collectors/Pet trade Loss of CRLF populations

9 San Francisco Garter Snake (Thamnophis sirtalis tetrataenia)

10 Turquoise colored belly scoots of a San Francisco Garter Snake (Thamnophis sirtalis tetrataenia)

11 Adult Common or Valley Garter snake Thamnophis sirtalis fitchi eating a western toad

12 San Francisco Garter Snake (Thamnophis sirtalis tetrataenia)

13 SFGS EAT CRLF ADULTS, JUVINELS AND TADPOLES

14 Jessica Wheeler Pacific Treefrog Pseudacris sierra (formerly Hyla regilla)

15 Requirements San Francisco Garter Snake (Thamnophis sirtalis tetrataenia) Ponds with tadpoles & frogs (food) Basking areas Deep water escape from raccoons and other mammalian predators Overhead escape cover form birds grasslands or coastal scrub with mammal burrows or dense vegetation for cover

16 Upland Requirements San Francisco Garter Snake (Thamnophis sirtalis tetrataenia) Need earthen areas that stay insulated (warm) and dry during cold, wet winter months. For example, grasslands or coastal scrub with mammal burrows. Earth mounds above high water/flood zone that have a mix of coastal scrub and native grass can be made. Need basking areas with immediate escape cover from birds or mammalian predators. For example an exposed earthen patch immediately adjacent to a shrub or dense tulles. (Note: SFGS give birth to live young. Other snakes such as Gopher snakes, lay eggs in a nest underground.)

17 Range Map from the USFWS 1985 SFGS Recovery Plan Six sites identified for Recovery Actions 1. San Francisco Airport/Milbrae Site 2. San Francisco State Fish and Game Refuge (Upper & Lower Crystal Springs Reservoir) 3. Sharp Park Golf Course (Laguna Salada) 4. Pescadero Marsh Natural Preserve 5. Cascade Ranch 6. Ano Nuevo State Reserve

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19 Private agricultural ponds Lake Arrowhead Proposed Area for Laguna Salada & Sanchez Creek Tributary Restoration (Boundaries not Shown) Mori Point Existing ponds Legend Shallow frog and snake pond Daylight Sanchez Creek Generalized area for SFGS corridor Area for SFGS overpass or underpass Figure 9. Dedicated area along Sanchez Creek for future restoration of a San Francisco Garter Snake movement into and out of the Lagoon at Sharp Park and Mori Point to Lake Arrowhead east of HYW1, with a land bridge, either under or over HWY and roadways.

20 California Red-legged Frog (Rana draytonii) (formerly classified as Rana aurora draytonii) Reasons for Population Decline Habitat Removal Stream Degradation and Diversions Non-native predators (crayfish, bass and bullfrogs) Farmed and hunted as a food frog

21 California Red-legged Frog Aquatic Areas: Marshy habitats, springs, both natural and artificial ponds, slack water pools of rivers and streams. Tidally influenced coastal marshes under certain conditions. They need SEASONAL freshwater: many tidal areas provide freshwater seasonally.

22 California Red-legged Frog (Rana aurora draytonii) Upland Habitat Upland habitat within 2 or more, of suitable aquatic habitat. However, they are usually found close to the waters edge. They have been documented to spend as much as 77 days away from water. Upland areas need to be moist! Leaf litter, fog, under logs, mammal burrows. Adults eat Pacific tree frogs, mice and insects.

23 Description: Vary in coloration. Strong dorsal lateral fold; a ridge behind each eye that extends down past the hip; Chin Strap. 4 cm to 15 cm snout vent (total body length without legs), depending on age.

24 Note: Dorsal lateral fold from eye to hip California Red-legged Frog (Rana draytonii) Formerly classified as Rana aurora draytonii Dawn Reis

25 California Red-legged Frog Eggmass (left) Water depth and habitat needs for eggs, tadpoles, newly metamorphosed frog and adults are different. CRLF Eggmass less than 24 hours old CRLF Eggs Pacific Treefrog Eggmass

26 Species Recovery at Sharp Park/Laguna Salada: Four concepts in tandem

27 1) EXPAND EXISTING SFGS/CRLF POPULATIONS Additional potential CRLF reproductive ponds added for SFGS habitat Upland areas restored for CRLF and SFGS Extension of Lagoon for both potential habitat on the eastern edge of the lagoon (More from Peter later) Figure 6. Laguna Salada Feasibility Study Restoration Plan

28 2) Do not put all of your eggs in one basket The plan calls for a matrix of CRLF/SFGS ponds that are not vulnerable to saltwater on the east edge of the lagoon and up Sanchez Cr If a catastrophic event occurs (wave over-wash, virus, heavy parasite load), there would: a) be potential areas for CRLF reproduction to occur and survive during that year (not all the eggs are in one basket) and b) refuge habitat for adult and sub-adult CRLF to move to.

29 Figure 6. Additional CRLF reproductive ponds outside

30 3) CONNECTIVITY Look for future opportunities to connect SFGS populations and allow for potential genetic flow into and out of Sharp Park either over or under HWY 1. This is critical for the SFGS recovery as human urban populations continue to grow way after you and I are gone (plan long term, think long term-over 100 years).

31 Private agricultural ponds Lake Arrowhead Proposed Area for Laguna Salada & Sanchez Creek Tributary Restoration (Boundaries not Shown) Mori Point Existing ponds Legend Shallow frog and snake pond Daylight Sanchez Creek Generalized area for SFGS corridor Area for SFGS overpass or underpass Figure 9. Dedicated area along Sanchez Creek for future restoration of a San Francisco Garter Snake movement into and out of the Lagoon at Sharp Park and Mori Point to Lake Arrowhead east of HYW1, with a land bridge, either under or over HWY and roadways.

32 4) Long term monitoring: Data is the mechanism for Effective Adaptive Management Long term monitoring of SFGS needs and threats is of great value and requires commitment. The value is that needs and treats can be addressed and effective Adaptive Management can occur. Areas include Arrowhead Lake, new sag ponds, Sanchez Cr, the lagoon, Horse Stable Pond, and upland habitats

33 Data is the mechanism for Adaptive Management Continued: This requires that different surveys occur that are specifically timed and focused for a) SFGS b) CRLF frogs & tadpoles c) Treefrog frogs & tadpoles d) non-native fish and b) non-native bullfrogs It also means water quality monitoring for fertilizer run-off and contamination from golf greens and storm drains. Aquatic areas to be included are the lagoon, Horse Stable Pond, Arrowhead Lake and Sanchez Cr and new sag ponds.

34 Species Recovery: Four concepts in tandem 1.Extend the potential habitat areas for SFGS and CRLF, make them more robust 2.Create a matrix of potential SFGS foraging areas by creating more potential habitat CRLF reproduction don t put all of your eggs in one basket 3.Connect potential habitat areas allow for genetic flow east and west of HWY 1 4. Conduct and use monitoring data as the mechanism for Adaptive Management

35 Peter Baye